Movable Type is, perhaps shockingly, still being actively developed; version 9 is coming out later this year. I’m not sure who the customer base is at this point—some years ago, they dropped the open source version and personal pricing and went to a very enterprise-ish $499/yr model—but I guess somebody is still giving them money.
That’s fair; it just makes it pretty steep at the low end compared to many other hosted solutions like Ghost, WordPress, or Squarespace. It gives the strong impression that they’re not looking for new customers as much as trying to keep existing commercial ones on board for as long as possible.
